To cite abtest in publications use:

Gronau QF, Raj K. N. A, Wagenmakers E (2021). “Informed Bayesian Inference for the A/B Test.” Journal of Statistical Software, 100(17), 1–39. doi:10.18637/jss.v100.i17.

Corresponding BibTeX entry:

  @Article{,
    title = {Informed {B}ayesian Inference for the {A}/{B} Test},
    author = {Quentin F. Gronau and Akash {Raj K. N.} and Eric-Jan
      Wagenmakers},
    journal = {Journal of Statistical Software},
    year = {2021},
    volume = {100},
    number = {17},
    pages = {1--39},
    doi = {10.18637/jss.v100.i17},
  }